Gas logs



L. F. BROOKS Dec. 13, 1966 GAS LOGS 2 Sheets-Sheet 1 Filed Au 4, 1964- United States Patent 3,291,116 GAS LOGS Lorirner P. Brooks, Briarclitf Manor, N.Y. (165 Broadway, New York, N.Y.) Filed Aug. 4, 1964, Ser. No. 387,385 9 Claims. (Cl. 12692) This invention relates to gas burning apparatus and particularly to apparatus of the type known as gas logs.

Gas logs are well known in the art for use in fireplaces and usually consist of some form of gas burner associated with simulated wood logs of non-combustible material, such as clay, metal, materials of the type described in US. Patent No. 2,762,362, etc. Some of such logs give a reasonably realistic effect, that is, partially simulate the appearance of a natural, wood burning fire, but the combustion systems or flame modifying arrangements employed in such logs are not acceptable by the standards of the American Gas Association (hereinafter referred to as AGA). Due to faulty operation of gas appliances sometimes encountered, the regulations relating to such appliances have become more strict over the years and many customers or state or local authorities require that the applances meet the standards of the AGA before they may be installed.

In an effort to comply with such standards, gas logs have been developed which employ gas burners of the type commonly used in gas stoves, furnaces, etc. However, With the normal gas pressures encountered in the home, for example, a pressure of six to eight inches of water, the flame issuing from such a burner has a height of only one-half to one inch above the tops of the ports in the burners. Furthermore, the flame height is relatively uniform and because of this, as Well as the small height thereof, gas logs employing such burners do not provide the natural effect of a wood burning fire.

More realistic effects have been obtained by having the flame from such a burner impinge upon the logs. However, in order to accomplish this, the logs or portions thereof must be brought within approximately one inch or less of the tops of the burner ports and the present requirements of the AGA do not permit such placement of the logs, the theory being that in order to obtain proper combustion, the cones of flame must be free to form above the ports and, therefore, no object can be within the cone forming area. Generally speaking, the AGA standards required that there be a free area both at the sides of the ports for the purpose of supplying combustion air and for at least one-half inch above the tops of the free flames. In addition, the free areas must exist even when the burner is operated with a gas presure fifty percent greater than normal.

I have discovered that when the ports of such a burner are surrounded by a substantially impervious wall, which is spaced at its lower end from the ports and which forms an opening above the ports having an area less than the cross-sectional area of the free flames, the height of the flames may be increased ten to twenty times. Also, after the flames issue from said opening, they will be irregular in height without special shaping of the opening and they may impinge upon an object, such as a simulated log, without interfering with the combustion. A gas log so equipped may be constructed to meet the requirements of the AGA and provides a very realistic effect, closely approximating the appearance of a wood burning fire. Due to the nature of the action which results from the use of such wall, it has been called a flame accelerator.

One object of the invention is to provide a device which will increase the height of the flames obtainable with a conventional gas burner.

A further object of the invention is to provide a gas log, particularly useful in fireplaces, which gives an appearance similar to that obtained with a wood burning fire.

Other objects of the invention will be apparent from the following detailed description of the new preferred embodiments thereof, and from the accompanying drawings in which:

FIG. 1 is a side elevation view of a preferred embodiment of the gas logs of the invention;

FIGS. 2 and 3 are, respectively, fragmentary plan and front elevation views of the embodiment shown in FIG. 1 with the simulated logs removed;

FIGS. 4 and 5 are, respectively, front and side elevation views showing a modified form of the flame accelerator in association with a gas burner;

FIGS. 6 and 7 are, respectively, front and side elevation views of another form of the flame accelerator in association with a gas burner; and

FIGS. 810 are, respectively, front elevation plan and side elevation views of a further form of the flame accelerator in association with a gas burner.

While the principles of the invention may be employed with gas logs which do not meet the requirements of the AGA, the prefered form of the invention, illustrated in FIGS. 1-3, has been tested by and meets the requirements of the AGA. Accordingly, if it is not necessary to meet the requirements of the AGA, the dimensions hereinafter set forth may be varied beyond the limits specified as necessary to meet AGA requirements.

The gas log illustrated in FIGS. 13 comprises a stand 10 having legs 11 and brackets 12 and 13, the brackets 12 and 13 being used to support the non-combustible, simulated wood logs 14 and 15. A conventional gas burner 16 is mounted on the stand 10 and has a plurality of ports 17 directed upwardly and from which the gas-air mixture issues to form flames after ignition thereof. Gas is supplied to the ports 17 through the opening 18 which receives a conventional gas orifice (not shown) attached rows of ports 17, each row being approximately 13 inches long and being separated from the other by approximately one-half an inch. There were eighty ports, each oneeighth of an inch in diameter. When connected to a natural gas main with a gas pressure of approximately six inches of water, each row produced a flame approximately one-quarter of an inch wide a short distance above the ports 17 and thirteen inches long, the top of the flame being approximately one-half an inch above the top of the ports 17. At a short distance away from the top of the ports, the flames of each row come together at their sides forming a flame having a cross-sectional area of approximately thirteen square inches. When the pressure of the gas is increased, the flame height increases and with a pressure of approximately nine inches of water, the flame height normally is between approximately one inch and one and one-half inches, when the shutter 20 is properly adjusted.

The flame accelerator of the invention is designated generally by the reference numeral 22. In the preferred form of the invention, a flame accelerator 22 has four converging walls, a pair of end walls 23 and 24 and a pair of side walls 25 and 26. Since in the preferred form of the invention the dimensions of the accelerator 22 are such that the free flames do not impinge thereon, and since the action of the accelerator is such that the flames are separated from the inner surfaces of the walls by a thin fllm of air resulting from the flow of air alongside the ports 17, such as indicated by the arrows 27 and 28, the accelerator 22 is not heated to high temperatures and, therefore, the accelerator 22 may be constructed of relatively inexpensive material, such as cold-rolled or hotrolled steel. However, it will be apparent to those skilled in the art that other non-combustible materials may be employed, particularly if dimensions are used which permit the free flames to impinge upon the walls of the accelerator 22.

The end walls 23 and 24 are secured to the side walls 25 and 26, such as by welding, and, in order to prevent bending of the upper portions of the side walls 25 and 26, they may be provided with flanges 29 and 30 or other known reenforcing means. As shown in FIGS. l-3, the flange 30 may be wider than the flange 29 so as to provide support for the simulated log 15, but if desired, may have the same width as the flange 29. Both of the flanges 29 and 30 may be omitted if desired. The accelerator 22 is mounted over the burner 16 with the upper opening 31 therein aligned with the central plane of the burner 16. To permit contraction and expansion of the accelerator 22 without buckling, it is preferably secured to the stand only at the two opposite corners, such as by the brackets 32 and 33. Preferably also, the accelerator 22 is separated from the stand 10 by the thickness of the brackets 32 and 33 so as to keep conductive contact between the accelerator 22 and the stand 10 to a minimum, thereby reducing the heat transfer from the accelerator 22 to the stand 10 and maintaining the stand 10 relatively cool.

It will be apparent that the accelerator 22 forms a tubular member or wall with its lower and extending around, but spaced from, the ports 17. The spacing between the inner surface of the side walls 25 and 26 from the ports 17 preferably is the same and is made large enough to provide suflicient air to the flames for proper combustion. With a burner of the type described above, the spacing indicated by the letter C may, for example, be approximately one-half to one inch.

The inner surfaces of the end and side walls, which are closest in a vertical direction to the tops of the ports 17, is preferably made, in order to comply with AGA requirements, at least one-half .an inch greater than the height of the free flames above the ports 17. Thus, the dimension B, indicated in FIG. 1, may be of the order of one and one-half to two inches, depending on the free flame height with normal and fifty percent greater than normal gas pressure. The distance of the opening 31 from the tops of the ports 17 as indicated by the dimension A in FIG. 1, should be as short as possible in order that the accelerator 22 may be hidden behind the simulated log without requiring a large log 15 and, in order to obtain the desired effects, preferably it is no greater than eight to ten times the height of the free flames above the ports 17. In the preferred embodiment shown, it is approximately two and one-half inches.

The size of the opening 31 is less than the cross-sectional area of the free flames issuing from the ports 17.

' ignited gas-air containing chamber.

Thus, in the example given, the cross-sectional area of the free flames is approximately thirteen square inches and, therefore, the area of the opening 31 should be less than thirteen square inches. Satisfactory results have been obtained with normal gas pressure and the burner described above employing openings 31 having sizes varying from three-eights of an inch wide and twelve inches long to three-fourths of an inch wide and thirteen inches long. With an opening three-eighths by twelve inches, flames as high as thirteen inches or more above the ports have been obtained, and with an opening 31 of three-fourths by thirteen inches, flame heights of four to five inches have been obtained. A larger opening aids in preventing contact of the flames with the accelerator 22 with above normal gas pressures. It will thus be apparent that the height of the flame varies with the size of the opening 31, small openings giving higher flames, and larger openings giving lower flames. If the area of the opening 31 is as large or larger than the cross-sectional area of the free flames, there is substantially no increase in flame height.

Other types of burners may be employed such as those with drilled ports or the so-called ribbon burner in which the ports are defined by spaced ribbons. However, with each type the size of the opening 31 is determined by the cross-sectional area of the free flames.

Although the gas issuing from the ports 17 may be ignited from underneath the accelerator 22, such an operation is undesirable because, generally, the user will attempt to ignite the gas at the opening 31. It has been found that when the opening 31, under the conditions given, is slightly less than three-eighths by twelve inches, and an attempt is made to ignite the gas at the opening 31, the gas does not ignite at the ports 17, but instead ignites above the opening 31, the accelerator 22 forming an un- This, of course, is undesirable not only from the standpoint of the AGA standards, but also from the standpoint that if the gas is allowed to accumulate within the accelerator 22 before it is ignited, a mild explosion results upon ignition. In addition, the flame tends to lift above the accelerator 22, permitting unburned gas to escape. Accordingly, in the preferred embodiment of the invention, the opening 31 has an area of at least one-third the cross-sectional area of the free flames.

The height of the flames is also effected by the position of the lower edge 32 of the accelerator 22 with respect to the tops of the ports 17. With the lower edge 32 substantially at the level of the tops of the ports 17, the flame height is lower with a given size opening 31 than it is when the lower edge 32 is below the level of the tops of the ports 17. In addition, when the opening 31 is relatively small, and the lower edge 32 is at the level of the tops of the ports 17, flames undesirably flow around the edge 32 below such edge. Such undesirable flames below the edge 32 may be eliminated by reducing the gas pressure, but this is accompanied by a loss of flame height. In the preferred form of the invention, the lower edge 32 is below the level of the tops of the ports 17 by at least one-eighth of an inch and preferably more.

In the preferred form of the invention, the rear simulated log 14 has a portion 33 which extends over the opening 31 so that the flames 34 issuing from the opening 31 contact or lap the simulated log 14. Preferably also, when the material employed for the logs is a material of the type described in US. Patent 2,762,362, the portion 33 has incorporated therein, small clumps of asbestos wool which will be made to glow by the flames 34, thereby creating the effect of burning embers. Log 15 may be omitted if desired and the appearance is otherwise acceptable.

Although the construction of the accelerator 22 illustrated in FIGS. 1-3 is preferred because of the ease with which it may be constructed, the shape of the accelerator 22 may take other forms, as illustrated in FIGS. 4l0. Thus, as shown in FIGS. 4 and 5, the accelerator 22a may have substantially vertical side wall portions 35 and 36 at the lower part thereof, and inwardly converging upper side Wall portions 37 and 38. When the lower portions of the walls are made substantially vertical, the end walls 36 may snugly engage the ends of the burner 16.

A further form of the accelerator 22 is shown at 22b in FIGS. 6 and 7. In this embodiment, the end walls 39 are substantially vertical throughout their heights, and the front side wall has a lower, substantially vertical portion 40, and a rearwardly extending upper portion 41. The rear side wall 42 may also be substantially vertical throughout its height.

A further modified form of the accelerator 22 is illustrated at 220 in FIGS. 810. In this embodiment, the flame accelerator 22c is formed by one continuous, inwardly curving wall i3, having an opening 31a corresponding to the opening 31 illustrated in FIG. 2.

Having thus described my invention with particular reference to the preferred form thereof and having shown and described certain modifications, it will be obvious to those skilled in the art to which the invention pertains after understanding my invention, that various changes and other modifications may be'made therein without departing from the spirit and scope of my invention, as defined by the claims appended thereto.

What is claimed as new and desired to be secured by Letters Patent is:

l. A gas burning assembly comprising an elongated gas burner having ports directed in a predetermined direction, said ports being adapted to provide a gas flame of a predetermined cross-sectional area, and a tubular flame accelerator mounted over said burner with its bore aligned with said predetermined direction and with one end adjacent said ports, said accelerator having an upwardly converging continuous wall with a bottom opening at said one end which is larger than the periphery of said ports, whereby the inner surface of said accelerator at said one end is spaced from said ports and said accelerator having a top opening at its opposite end which is less in area than said predetermined flame area.

2. A gas burning assembly comprising an elongated gas burner having ports directed in a predetermined direction, said ports being adapted to provide a gas flame of a predetermined length and width and of a predetermined height, and a tubular flame accelerator mounted over said burner with its bore aligned with said predetermined direction and with one end adjacent said ports, said accelerator having an upwardly converging continuous wall with a bottom opening at said one end which is larger than the periphery of said ports, whereby the inner surface of said accelerator at said one end is spaced from said ports and said accelerator having a height greater than said predetermined height and a top opening at its opposite end which is shorter and narrower respectively than said predetermined flame length and width.

3. A gas burning assembly comprising an elongated gas burner having ports directed in a predetermined direction, said ports being adapted to provide a gas flame of a predetermined cross-sectional area and of a predetermined height, and a flame accelerator mounted over said burner, said accelerator having a substantially imper-forate upwardly converging continuous wall extending around said ports and spaced therefrom, said wall extending in said predetermined direction from at least the level of said ports to a point more remote from said ports than said predetermined height, said wall at the portion thereof remote from said ports forming an opening having an area less than said predetermined flame area.

4. A gas burning assembly comprising an elongated gas burner having ports directed in a predetermined direction, said ports being adapted to provide a gas flame of a predetermined cross-sectional area and of a predetermined height, and a flame accelerator mounted over said burner, said accelerator having a substantially imperforate upwardly converging continuous wall extending around said ports and spaced therefrom, said wall extending in said predetermined direction from below the level of said ports to a point more remote from said ports than said predetermined height, but less than ten times said predetermined height, said wall at the portion thereof remote from said ports forming an opening having an area less than said predetermined flame area but at least one-third of said predetermined flame area.

5. A gas log comprising an elongated gas burner having ports directed in a predetermined direction, said ports being adapted to provide a gas flame of a predetermined cross-sectional area, a tubular flame accelerator mounted over said burner with its bore aligned with said predetermined direction and with one end adjacent said ports, said accelerator having an upwardly converging continuous wall with a bottom opening at said one end which is larger than the periphery of said ports, whereby the inner surface of said accelerator at said one end is spaced from said ports and said accelerator having a top opening at its opposite end which is less in area than said predetermined flame area, and at least one non-combustible simulated log mounted at one side of said accelerator.

6. A gas log comprising an elongated gas burner having ports directed in a predetermined direction, said ports being adapted to provide a gas flame of a predetermined cross-sectional area, a tubular flame accelerator mounted over said burner with its bore aligned with said predetermined direction and with one end adjacent said ports, said accelerator having an upwardly converging continuous wall with a bottom opening at said one end which is larger than the periphery of said ports, whereby the inner surface of said accelerator at said one end is spaced from said ports and said accelerator having a top opening at its opposite end which is less in area than said predetermined flame area, and non-combustible simulated logs mounted on opposite sides of said accelerator.

7. A gas log comprising a stand, an elongated gas burner mounted on said stand, said burner having upwardly directed ports adapted to provide a gas flame having a predetermined cross-sectional area and a predetermined height, a flame accelerator mounted over said burner, said accelerator having converging side walls extending substantially parallel to the length of said burner and from below said ports to above said predetermined height and being spaced from said burner and said accelerator having end walls joining said side walls, said side and end walls having their inner surfaces spaced from said flame and forming an opening above said ports having an area less than said predetermined flame area, and a noncombustible simulated log mounted on said stand at one side of said accelerator.

8. A gas log comprising a stand, an elongated gas burner mounted on said stand, said burner having upwardly directed ports adapted to provide a gas flame having a predetermined cross-sectional area and a predetermined height, a flame accelerator mounted over said burner, said accelerator having converging side walls extending substantially parallel to the length of said burner and from below said ports to above said predetermined height but less than ten times said predetermined height and being spaced from said burner and said accelerator having end walls joining said side walls, said side and end walls having their inner surfaces spaced from said flame and forming an opening above said ports having an area less than said predetermined area but at least equal to onethird of said predetermined flame area, and a non-combustible simulated log mounted on said stand at one side of said accelerator.

9. A gas log comprising a stand, an elongated gas burner mounted on said stand, said burner having upwardly directed ports adapted to provide a gas flame hav ing a predetermined cross-sectional area and a predetermined height, a flame accelerator mounted over said burner, said accelerator having converging side walls extending substantially parallel to the length of said burner and from below said ports to above said predetermined height but less than ten times said predetermined height and being spaced from said burner and said accelerator having end walls joining said side walls, said side and end walls having their inner surfaces spaced from said flame and forming an opening above said ports having an area less than said predetermined area but at least equal to one-third of said predetermined flame area, and non-combustible simulated logs mounted on said stand on opposite sides of said accelerator, one of said logs having a portion extending over said opening in said accelerator.

8 References Cited by the Examiner UNITED STATES PATENTS 1,381,092 6/1921 Kolva 158l13 1,395,404 11/1921 Flick 158--1l3 1,546,919 7/1925 Dore.

2,084,566 6/1937 Warfield 126-92 2,762,362 9/1956 Nielsen 12692 3,042,109 7/ 1962 Peterson 12692 X 10 FREDERICK L. MATTESON, IR., Primary Examiner.

R. A. DUA, Assistant Examiner. 

1. A GAS BURNING ASSEMBLY COMPRISING AN ELONGATED GAS BURNER HAVING PORTS DIRECTED IN A PREDETERMINED DIRECTION, SAID PORTS BEING ADAPTED TO PROVIDE A GAS FLAME OF A PREDETERMINED CROSS-SECTIONAL AREA, AND A TUBULAR FLAME ACCELERATOR MOUNTED OVER SAID BURNER WITH ITS BORE ALIGNED WITH SAID PREDETERMINED DIRECTION AND WITH ONE END ADJACENT SAID PORTS, SAID ACCELERATOR HAVING AN UPWARDLY CONVERGING CONTINUOUS WALL WITH A BOTTOM OPENING AT SAID ONE END WHICH IS LARGER THAN THE PERIPHERY OF SAID PORTS, WHEREBY THE INNER SURFACE OF SAID ACCELERATOR AT SAID ONE END IS SPACED FROM SAID PORTS AND SAID ACCELERATOR HAVING A TOP OPENING AT ITS OPPOSITE END WHICH IS LESS IN AREA THAN SAID PREDETERMINED FLAME AREA. 